The present invention relates generally to a system and method for the treatment of disorders of the vasculature. More specifically, a system and method for treatment of an abdominal aortic aneurysm and the like, which is a condition manifested by expansion and weakening of the aorta. Prior methods of treating aneurysms have consisted of invasive surgical methods with graft placement within the affected vessel as a reinforcing member of the artery. However, such a procedure requires a surgical cut down to access the vessel, which in turn can result in a catastrophic rupture of the aneurysm due to the decreased external pressure from the surrounding organs and tissues, which are moved during the procedure to gain access to the vessel. Accordingly, surgical procedures can have a high mortality rate due to the possibility of the rupture discussed above in addition to other factors. Other risk factors for surgical treatment of aortic aneurysms can include poor physical condition of the patient due to blood loss, anuria, and low blood pressure associated with the aortic abdominal aneurysm.
Due to the inherent risks and complexities of surgical intervention, various attempts have been made to develop alternative methods for deployment of grafts within aortic aneurysms. One such method is the non-invasive technique of percutaneous delivery by a catheter-based system.
U.S. Patent Application Publication No. US 2004/0138734, which is incorporated herein in its entirety by reference, describes systems and methods for the delivery of endovascular grafts, including bifurcated grafts. FIG. 1 illustrates a delivery system 10 of such publication for delivery and deployment of a bifurcated intracorporeal device 12 within a patient's body. The delivery system 10 includes an elongate shaft 14 having a proximal section and a distal section. The bifurcated intracorporeal device 12 is disposed on the distal section of the elongate shaft 14. The distal section of the elongate shaft 14 also includes an elongate primary belt support member 16 and at least one primary belt 18 secured to the primary belt support member 16. The primary belt 18 is configured to be circumferentially disposed about a primary portion 15 of the bifurcated intracorporeal device 12 to constrain such portion 15 of the device 12. A primary release member 20 engages and releasably secures the primary belt 18 in the constraining configuration. The distal section of the elongate shaft 14 also includes at least one elongate secondary belt support member 22 disposed adjacent the elongate primary belt support member 16. At least one secondary belt 24 is secured to the secondary belt support member 22 and is configured to be circumferentially disposed about a secondary leg portion 23 of the bifurcated intracorporeal device 12 to constrain such portion 23 of the device 12. A secondary release member 26 engages and releasably secures the secondary belt 24 in a constraining configuration.
The distal end of the delivery system 10 is introduced into the patient's body and advanced to a desired site within the patient's body. The delivery system 10 generally delivers the bifurcated intracorporeal device 12 via a single patient lumen or vessel, for example, either the left or right iliac (or femoral) artery. After the delivery system has been positioned above the carina of the iliac artery bifurcation, the secondary belt support member 22, and thereby the secondary leg portion 23, is moved laterally to align with the other of the iliac arteries. To facilitate such, a release strand 28, comprising first and second strands 27 and 29, is looped through a proximal portion of the secondary support member 22. The distal ends of the strands 27 and 29 are interconnected at an actuator hub 30 while the opposed proximal ends of strands 27 and 29 are directed out a secondary opening from the other of the iliac (femoral) arteries. As shown in FIG. 1, the secondary release member 26 is also attached to the actuator hub 30. When both strands 27 and 29 are pulled equally, they can be utilized to pull the secondary support member 22, but they do not cause any relative movement to the secondary release member 26 since the strands 27 and 29 apply an equal force to the actuator hub 30. To release the secondary belt 24, strand 29 is pulled proximally such that the actuator hub 30, and thereby the secondary release member 26, will be pulled proximally until the secondary release member releases the secondary belt 24.
To assist in directing of the strands 27 and 29 of the release strand 28 toward the secondary opening in the other of the arteries, the release strand 28 may initially be covered by a tube 32 or sheath or the like. During initial delivery of the delivery system 10, the tube 32 may either be fished, directed along a guide wire, or otherwise directed through the secondary opening. After the tube 32 is directed through the secondary opening, the tube 32 is removed from the release strand 28 such that both strands 27 and 29 are exposed.